Re: [PATCH] mtd: partitions: fix of_node_get/put balance in parser

[Boris Brezillon <boris.brezillon@bootlin.com>]

On Mon, 17 Sep 2018 11:55:20 +0200
Miquel Raynal <miquel.raynal@bootlin.com> wrote:

> > Or you just say that mtd_get_of_node() does not retain a reference to
> > the device_node object it returns and that should be enough ;-).  
> 
> Fine by me, you can apply it and modify in place.

Here is the new commit message:

"
mtd: partitions: fix unbalanced of_node_get/put()

While at first mtd_part_of_parse() would just call
of_get_chil_by_name(), it has been patched to deal with sub-partitions
and will now directly manipulate the node returned mtd_get_of_node() if
the MTD device is a partition.

A of_node_put() was a bit below in the code, to balance the
of_get_child_by_name(). However, despite its name, mtd_get_of_node()
does not take a reference on the OF node. It is a simple helper
hiding some pointer logic to retrieve the OF node related to an MTD
device.
    
The direct effect of such unbalanced reference counting is visible
by rmmod'ing any module that would have added MTD partitions:

	OF: ERROR: Bad of_node_put() on <of_path_to_partition>

As it seems normal to get a reference on the OF node during the
of_property_for_each_string() that follows, add a call to
of_node_get() when relevant.
    
Fixes: 76a832254ab0 ("mtd: partitions: use DT info for parsing partitions with "compatible" prop")
Cc: stable@vger.kernel.org
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
"

Let me know if you're okay with this update.

Thanks,

Boris